"Why check in online?
Checking in online pays off when you get to the airport. And, you'll board in Zone 3. (If you're Dividend Miles Preferred, you'll still board in Zones 1 and 2 depending on your Preferred status.)"


Also notable is that if you have a FF number in your record from a *A carrier and you are *A Gold, you will get zone 1. If you are *A Silver, you will get zone 2.